1. Field of the Invention
The present invention relates to a transmitter-receiver unit for a portable telephone and more particularly to a transmitter-receiver unit for a portable telephone which is applicable to both a right-hand antenna type portable telephone and a left-hand antenna type portable telephone.
2. Description of the Related Art
With reference to drawings, a description will be given below of a right-hand antenna type portable telephone using a conventional transmitter-receiver unit for a portable telephone.
FIG. 5 is a sectional view of a right-hand antenna type portable telephone using a conventional transmitter-receiver unit for a portable telephone, FIG. 6 is a plan view of a principal portion thereof, FIG. 7 is an exploded perspective view thereof, and FIG. 8 is a sectional view thereof.
As shown in FIGS. 5 to 8, a case 21 is formed in a generally box shape by molding using a synthetic resin and it comprises side walls 21a as surrounding walls, as well as a surface wall 21b and a back wall 21c which close the upper and lower sides, respectively, of the space defined by the side walls.
A mother board 22 is formed in the shape of a flat plate using an insulating resin material. On the mother board are mounted electronic components (not shown) such as a memory element for the storage of telephone numbers, etc. and an arithmetic element for carrying out various arithmetic operations, as well as a male connector 22a having a plurality of terminals. The mother board 22 is disposed within the case 21 in proximity to the back wall 21c and is secured to the case 21 by a suitable means.
An antenna 24 is formed in a generally cylindrical shape using, for example, a magnetic material and it is for the transmission and reception of, for example, voice signals. The antenna 24 has a rod-like antenna portion 24a capable of being drawn out to the exterior, a knob portion 24b formed at the tip of the antenna portion 24a, and a cylindrical portion 24c for receiving the antenna portion 24a therein.
In the antenna 24, the knob portion 24b of the antenna portion 24a is disposed on the right-hand side of the case 21 in an outwardly projecting state and the cylindrical portion 24c which accommodates the antenna portion 24a therein is disposed inside the case 21 and in proximity to the right-hand side wall 21a.
A transmitter-receiver unit 25 for a portable telephone has a flat plate-like printed wiring board 26 and a generally box-shaped frame 27 for holding the printed wiring board 26.
The printed wiring board 26 is provided on a first side (for example, the surface) thereof with electric components 26a such as crystal oscillator and coil, an antenna terminal member 26b connected to the antenna 21 and formed at a right-hand corner position, an antenna duplexer 26g connected to the antenna terminal member 26b, and a wiring pattern (not shown) of a desired shape. The printed wiring board 26 is also provided on a second side (for example, the back) thereof with electric components 26d such as an integrated circuit (LSI), a chip resistor and a chip capacitor, a female connector 26c having a plurality of terminals (not shown), and a wiring pattern (not shown) of a desired shape.
With the electric components 26a, 26d and the wiring pattern (not shown) there are constituted a transmission circuit block (not shown) which outputs to the antenna 24 a transmission signal for transmitting a signal of voice and the like from the antenna and a reception circuit block (not shown) which receives a reception signal from the antenna 24 and outputs a voice signal on the basis of the reception signal. Both the transmission circuit block and the reception circuit block are connected to the antenna duplexer 26g. A connecting terminal (not shown) of the antenna 24 is connected, for example by soldering, to the antenna terminal member 26b formed at a right-hand corner position of the printed wiring board 26.
The frame 27 is formed in a generally box shape by cutting and bending a metallic flat plate and it comprises side walls 27a as surrounding walls, a bottom wall 27b which closes the lower surface side, and a receptacle portion whose upper surface side is open. In the bottom wall 27b is formed a rectangular hole 27d.
The printed wiring board 26 is mounted and held in the receptacle portion 27c of the frame 27 with use of a suitable means. In this state, the board 26 is located in proximity to the bottom wall 27b, and the female connector 26c is inserted into the hole 27d of the bottom wall 27b.
The transmitter-receiver unit 25 having the printed wiring board 26 and the frame 27 is placed on the mother board 22.
In this state, the male connector 22a of the mother board 22 and the female connector 26c of the printed wiring board 26 are electrically connected with each other. Further, the antenna 24 and the transmitter-receiver unit 25 are located adjacent each other on the mother board 22.
The following description is now provided about a left-hand type portable telephone using the conventional transmitter-receiver unit.
In this left-hand antenna type portable telephone, an antenna is disposed on the right-hand side of a case and an antenna terminal member of a printed wiring board is disposed at a left-hand corner position of the same board, the antenna and the antenna terminal member being connected with each other.
As described above, in the right-hand antenna type portable telephone using the conventional transmitter-receiver unit for a portable telephone, the antenna mounted on the right-hand side of the case and the antenna terminal member disposed at a right-hand corner position of the printed wiring board are connected with each other, and the female connector disposed on the second side (for example, the back) of the printed wiring board and the male connector disposed on the mother board are connected with each other.
However, both the right-hand antenna type portable telephone and the left-hand antenna type portable telephone as a type contrast thereto are popular. In the transmitter-receiver unit used in the left-hand antenna type portable telephone, the antenna is disposed on the left-hand side of the portable telephone, so that the antenna terminal member of the printed wiring board in the transmitter-receiver unit is required to be located at left-hand corner position of the printed wiring board and design is made to meet the requirement.
Thus, in the conventional transmitter-receiver unit for a portable telephone, since the antenna terminal member for the printed wiring board in the left-hand antenna type portable telephone is disposed at a left-hand corner position, separate such transmitter-receiver units are designed, one for the right-hand antenna type portable telephone and the other for the left-hand antenna type portable telephone.
This is because the foregoing construction of the transmitter-receiver unit for the right-hand antenna type portable telephone is not directly applicable to the transmitter-receiver unit for the left-hand antenna type portable telephone in which the antenna terminal member is disposed at a left-hand corner position of the transmitter-receiver unit.
It follows that the transmitter-receiver units for the right and left antenna type portable telephones are required to be designed as separate units, thus giving rise to the problem that the number of design steps increases.